1. Field of the Invention
The present invention relates, in general, to a root canal plugging apparatus for dental work and, more particularly, to a complex root canal plugging apparatus consisting of a controller, a gun-type injection device, a pen-type vertical spreader, and a cradle for holding both the injection device and the spreader, thus allowing a dentist to more easily, rapidly and precisely pack a root canal with a filler material while performing a root canal plugging procedure during a nerve treatment in a dental clinic.
2. Description of the Prior Art
During a dental treatment for a decayed tooth in a dental clinic, a dentist appropriately removes decayed parts from the tooth using dental drills, reamers, files and burs, and performs a root canal plugging procedure for packing a root canal with a filler material, prior to covering the tooth packed with the filler material using a crown.
Typically, gutta-percha cones have been preferably used as such filler materials during the root canal plugging procedures. The gutta-percha is the milky juice of Malaysian trees of the sapodilla family, especially Palaguium or Payena trees, and has a semisolid phase at a normal temperature, but becomes a hard rubberlike gum when being compressed or heated. The gutta-percha in the form of such a hard rubberlike gum is so-called “white gutta-percha”. The dentally usable gutta-percha cones are produced by adding zinc oxide, barium sulfate, wax and pigment to the gutta-percha, and kneading them in a mixer prior to extruding the mixture in the form of a sheet using a roll. The sheet type extruded mixture is, thereafter, cut into pieces, and the pieces are shaped into cones to form desired gutta-percha cones having different sizes. The gutta-percha cones have been most widely used as the root canal filler materials since they are biologically compatible with living bodies and not harmful to the root apexes of human teeth.
The recently marketed gutta-percha cones include standardized cones and accessory cones. The standardized gutta-percha cones have the same shapes as the dental files. During a nerve treatment procedure for a decayed tooth, infected nervous tissues are primarily removed from the root of the decayed tooth through rotating and cutting actions of a file, thus forming a conical root canal in the tooth. Thereafter, the root canal is plugged with a gutta-percha cone having the same size as the file so as to prevent the root of the tooth from being reinfected. In dentistry, the procedure for plugging the root canal with a gutta-percha cone is so-called “a root canal plugging procedure”. In a conventional root canal plugging procedure, it is almost impossible to completely plug each root canal with one standardized gutta-percha cone, but five to eight cones are typically used for completely plugging the root canal since the root canal is not precisely formed during the procedure for forming the root canal using a file, and there remains a substantial gap between the standardized gutta-percha cone and the root canal wall. Such an inferior precision of the root canal is typically caused by unskillfulness of a dentist rather than inferior operational precision of the file.
When it is desired to plug a root canal having a size different from that of a file used in a procedure for forming the root canal, a standardized gutta-percha cone is primarily packed in the root canal until the cone reaches the root apex. Thereafter, the remaining empty portion in the root canal is secondarily packed with accessory cones using a spreader, thus completely plugging the root canal. However, such conventional procedures for plugging root canals with standardized and accessory gutta-percha cones consume much time, so it is very inconvenient to dentists and patients, in addition to giving pains to the patients. In addition, the conventional root canal plugging procedures using the standardized and accessory gutta-percha cones cannot completely plug an accessory canal with gutta-percha cones even though it is possible to plug a main canal with gutta-percha cones. Therefore, the root of a decayed tooth may be reinfected after treatment.
In the prior art, a variety of dental implements used in such root canal plugging procedures have been proposed. As examples, gun-type injection devices and pen-type spreaders, which are connected to separate controllers, have been proposed and used.
An example of such conventional dental implements for performing root canal plugging procedures is referred to U.S. Pat. No. 5,893,713, disclosing an apparatus consisting of an electric power control and a temperature controllable probe connected to the control. However, the apparatus disclosed in the above U.S. patent is problematic in that the resistance heater of the plugger element provided at the probe is too short in its length. Furthermore, the above U.S. patent does not disclose the material of the electric wire installed in the probe. When using a conventional electric wire in the probe, the wire causes a problem in that it provides an inferior electric conductivity in comparison with silver wires.
In addition, U.S. Pat. Nos. 5,934,903 and 6,168,432 each disclose a needle for filler material injection devices. However, the needles disclosed in the above U.S. patents are problematic in that it is very difficult to insert the needles into small-sized root canals. In addition, the hollow needles are not tapered, so they do not allow a smooth flowing of softened filler materials through them when inserting the filler materials into root canals, and, furthermore, the needles may be easily broken in root canals during root canal plugging procedures.